Transcript for Video of Oscar Pistorius Re-Enacting the Night of the Slaying Leaked

We'll find out. First, though, the Oscar Pistorius murder trial. A private video showing him reenacting the night she died, it's out now, and complicating a difficult case for him. Lama Hasan has the latest. Reporter: It's chilling. Showing Oscar Pistorius without his prosthetic legs acting out his movements the night he killed reeva steenkamp. It was meant as trial preparation for the defense. Will the prosecution pounce on it? This morning, Pistorius' team is condemning the airing of footage of the para limb Yan re-creating the night he shot dead his girlfriend as a staggering break of trust. The attorney says the channel paid for it, shows the olympian running awkwardly, outstretching his right arm as if clutching a gun. And slumped over in the bathroom, demonstrating the position her body was found. And struggling on the ground to carry a motionless woman. They hired a u.s.-based company to shoot the film for trial preparation only. It was never supposed to air during the trial. In a case that's weighed so heavily on his movement -- He can walk out the door of the bathroom. He can walk like he can walk? With his limitations yes, sir. Reporter: And using a sports medicine doctor to say he is vulnerable. Left without the benefit of his prosthesis does not allow him sufficient mobility or balance to protect himself and take flight. Reporter: The question this morning is whether the prosecution will use this video against him. New details from the psychology report describe Oscar Pistorius as a broken and lonely man. In the report, a clinical psychologist said he indicated that it would be easier if he were dead. The reason he hasn't taken his life, his family has been put through enough. It would be a lengthy process if the prosecution decides to use it. They would have to reopen the case if they want to present any more evidence in court. It's highly unlikely they will. And talk about it request Dan Abrams. And she hinted at this, maybe not worth it to get it in. Probably not. But it's an amazing video. This is Oscar Pistorius re-creating exactly what he says happened. So there's no question it's a compelling video, and I don't think there's almost any question it wouldn't come in. First of all, this was a video produced by the defense team. But why did they produce it? Well, look, it seems to me they were going to try to create an make or something of that sort as part of the defense, and asked him to re-create it. Maybe they wanted to know his side of the story. For whatever reason that they created it, it is apaling that it was leaked. What ever one of Oscar Pistorius -- Someone on his team probably. Even if you think he's totally guilty, the fact that some vender out there, it seems -- again, it seems -- leaked this video, is appalling. It's part of the defense preparation. I don't think prosecutors would have even asked to introduce it even if they weren't at the end of their case, knowing this is effectively part of the work product of the defense. But it would be valuable. If you're the prosecutor in this case, and you can use a video like this, you can go point by point and compare small discrepancies between what Pistorius said and what's on this video. You can also show him more mobile without his prosthetic legs than he's claimed at trial. It would be valuable, but I don't think prosecutors are going to ask for it. Really doesn't back up the story the defense told. A little bit different. It's the same basic story, but the devil's in the details. George is right, why make the tape in the first place? There are a lot of things that defense teams do that are surprising that people never find out about. Mock cross examinations, et cetera. This is an example. Thank you. Now to the young girl the

This transcript has been automatically generated and may not be 100% accurate.

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